Previous launch devices for single conductor transmission lines have used a simple conical shape structure to excite the surfacewave mode onto an insulated single conductor transmission line. In addition to having excess transmission attenuation due to losses in the dielectric insulation, these designs suffer from significant impedance mismatch, unwanted conversion to radiating modes and resultant transmission attenuation of the surfacewave mode when a broad range of frequencies is supported, and require both a longer cone and wider cone mouth in order to excite a surfacewave mode onto the single conductor. Special effort is also required to mount these previous designs onto the conductor, requiring that the transmission line be broken so that the launch may be threaded onto the line in order to be attached. This presents both mechanical and electrical challenges and limitations to the designer and installer of such a device, particularly if the launch apparatus is to be installed onto a pre-existing single conductor line.
The foregoing reflects the current state of the art of which the present inventor is aware. Reference to, and discussion of, this art is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the prior art discloses, teaches, suggests, shows, or otherwise renders obvious, either singly or when considered in combination, the invention described and claimed herein.